Since a static random access memory (SRAM) is large in standby energy and high in price, cache memories using nonvolatile memories have been researched. Among the nonvolatile memories, a magnetoresistive random access memory (MRAM) has high rewriting resistance, and is capable of realizing small cell size and high integration. However, from a point of view of access speed, the SRAM is far beyond the MRAM. In general, access speed and memory capacity have a trade-off relationship. Increase in the memory capacity lowers the access speed, while decrease in the memory capacity improves the access speed.
For example, in a case where a nonvolatile memory such as the MRAM and the like is used for a cache memory in lower-level, this cache memory may be concentratively accessed depending on application software executed by a processor. Therefore, compared to one that includes the SRAM, there is a possibility that processing performance may fall.